BIOS

When a computer powers up, the first thing you see is the BIOS software doing its work--usually just a few lines of type at the top of an otherwise black screen. The Basic Input-Output System, commonly known as BIOS, makes sure all the other chips, hard drives, ports and the computer’s central processing unit function together. BIOS provides the first instructions for the microprocessor to execute, and its most important role is to load the operating system.

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Researched by NONA YATES/Los Angeles Times

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